Cutting out...

All sorted now (i hope)

Got it back from AC Willaims yesterday and there is now nothing wrong with it electrically acording to their XR25. And it goes better too with the new CO POT!

Will take it for a good run over the weekend to check. Think you better follow me on sunday though Lee, just to be safe!!!

..i'm sure I mentioned something in this thread about hiring my diagnostic machine.... ..it saves a lot of time and money

Good to hear its running better, as I said it affects the low down torque and how the engine responds quite considerably...

FAILED!!!!!

Took her out for a good run yesterday, following Lee to the 'Chav Fest'. On the way there it cut out 2 or 3 times at speed. But only when i was pulling out of a right hand bend, not sure that the right hand bend had anything to do with it, but its odd that it only did it then, when it was under much more load on the straights....

When we got there and where in the traffic with the 'Chav's' it was an absolute nightmare. Nearly Everytime i pulled off to move down the line it died. If i could get the throttle down it would go and i could really 'boot it', but it cuts out different levels of throttle andyou can never tell when its going to happen...

Obviously heat has got something to do with it, so im thinking along the fuel route now. Maybe the pressure regulator or the fuel somehow evaperating before it gets to the pots?

I did think that maybe one of the fuel pumps was dodgy, but then it would happen all the time....

Ben, I know I have been banging on about the engine wiring harness that is a certain design disaster on the A610 and I have no experience of it on the GTA. However it is interesting to note that prior to repair and when my A610 was very hot and very moody, it would often drive backwards but instantly fail when going forwards. This did not greatly endear me to other road users!! The cause was making and breaking of poor internal junctions within the engine wiring harness. Just an inexpensive thought as you run out of other options!!!!

agreed, if its cutting out 'just like that' then its more likely to still be electrical than mechanical/fuel...

Ill give the wiring harness ago. I have already changed a few wires that looked dodgy. But i guess the time has come to spend a few days in the back with a soldering iron.

Ben, most important of all, a good digital mutimeter. Just measure the resistance everywhere from point to point and see what you get. Disconnected cables should read 0.1 or 0.2 ohm at worst. I was getting anything from 2.5 to 8.5 ohms and that is when I understood the problem.
Geoff

Thanks Geoff. Think ill start with the main earths in the engine bay first...

I think the approach is to suspect every cable and undo it and check it. Even a corroded earth can cause havoc. Having worked with vehicle electrics for 25 years, I have reached the conclusion that very few electronic components ever fail but the bits of string that join them all together do so most of the time. The good thing about my experience is that it rarely costs much money, only time and dedication. Good luck. It's great when you fix it and can trust it as I do mine now !!!!!

Just been taking some reading from the diagnostic tester of David's and the readings are as follows:

SENSOR TYPE = BENDIX

ECU CODE = 101.3

MAP SENSOR = 545 mB

CO POT = 1.002 VOLTS

IDLE POSITION = 8.19 %

These are the only reading i could get as the tester wouldn't work when the car was running - came up with "ECU NOT TALKING".

There were no fault showing up (other than "23 : NO RPM ENGINE SIGNAL, as it wasn't running").

Also tried it out on Clee's car and the results were the same other than his MAP SENSOR read 556 and his CO POT read 0.672 VOLTS.

Not sure if these results give anyone any ideas, but please shout out if they do?

I also got an open circut reading on the coolant temp,this would confirm the Prima report.All seems to be working OK tho, no unusual temps and the rad fans cut in when they should.I've looked at the wiring and all seems alright so I'm only left with the sensor itself If it aint broke don't eff with it.What reading should the CO pot give

They all seem fine (Lees c/o voltage seems a bit low though!). Was the battery voltage OK on the reader? Low voltage drop outs causes the ecu to turn off.

I was thinking of a list of all the bits you havent checked yet.

Ignition module - 3 wire plug is 12v and earth and tach output. Other two pin plug is trigger for spark firing from ecu. Check and clean
Get ignition module impedance tested
Earth strap to ignition module
Fuel pump connector, front and rear pump
Check connectors around ecu and main ecu plug
Fuel pump relay next to ecu
Check TDC sensor wiring and plug. If you have ever used brake cleaner or solvent in the engine bay, it melts the sheilding on the wiring for the sensor in seconds and can cause a short. Check for continuity with a multimeter

These are all physical things that the diagnostic reader can't pick up

You know in the end its going to be something so simple!

The CO pot voltage increased to 0.78 when I removed the sensor

0.78v is default get you home mode if you disconnect it.

Lee, I might have a tip that might make your car go SO much faster!

If your coolant temp sensor is reading open circuit then its probably knackered, evidence from that is the low c/o voltage. If the coolant sensor isnt working right then the car is permanently on choke and puts in 50% extra fuel than nessecary. On your last mot, it would have been running rich, so the tester would have adjusted the c/o level down to compensate, and thats why its set at such a low voltage.

If you fit the problem, it will have so much less lag, better performance on boost, better midrange, more torque.

Reset the system by disconnecting the battery for 15 secs and try the diagnostic again. If it comes up with the same fault, then once you sort it it will be so much better!

BTW, I have spare brand new sensors...

Does seem to be running a bit rich,sooty pipes still after fuel reg replacement.
Disconnected the battery twice last night and again this morning and still showing the coolant fault ( forgot to mention air temp fault on first check, but no longer ) .Whats the damage for a sensor then